Comparative and Evolutionary Physiology Commons^™

Molecular Characterization Of The Mummichog (Fundulus Heteroclitus) Ovarian Steroidogenic Pathway And Implications For Exogenous Estrogen Effects During Follicular Development, Thiviya Kanagasabesan

Theses and Dissertations (Comprehensive)

This study investigated ovarian development in Fundulus heteroclitus (mummichog), through molecular characterization of key mediators in the ovarian steroidogenic pathway; these included ovarian StAR (steroidogenic acute regulatory protein), cytochrome P450 enzymes, estrogen receptors (ERα, ERβ1 and ERβ2), and gonadotropin receptors (FSHr and LHr); additionally, hepatic vitellogenin (VTG1) and ERs, and brain P450 aromatase (P450arom; CYP19b) were studied. Fish were staged into cortical alveolus, vitellogenic, early mature, late mature, and ovulating stages of maturation; blood (plasma), ovary (tissue and isolated ovarian follicles per stage), liver, and brains were collected. Testosterone (T), 17β-estradiol (E₂) and maturation inducing steroid (MIS), measured …

Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali

Theses & Dissertations

Endocrine disrupting compounds (EDCs) are chemicals that interfere with hormone function and are increasingly detected in aquatic environments, where they elicit adverse effects from exposed organisms. The toxicological effects of EDCs can be described as either activational (reversible) or organizational (irreversible), where the latter are associated with adverse outcomes in reproductive performance of adult fish. However, few studies have investigated the organizational impacts of anti-estrogenic or “defeminizing” EDCs, e.g. agrichemicals or pharmacological agents, in an environmentally-relevant or “sentinel” species. The objective of this study was to investigate the impacts of early-life EDC-initiated changes in estrogenic gene expression on organizational effects …

The Effects Of Selection For High Voluntary Wheel-Running Behavior On Nutrient Canal Abundance And Size, Nicolas Lawrence Schwartz

Electronic Theses, Projects, and Dissertations

Variations in skeletal morphology have often been used to interpret an organism’s overall activity level when direct observation is not possible. Although skeletal change in response to exercise is well documented, the skeleton’s response to mechanical loading is modulated by several factors (e.g. age, hormones, sex). Additionally, variation in skeletal morphology is partially a result of genetic variation, which is rarely accounted for in inferences of locomotor activity from skeletal remains. However, blood flow to long bones serves as a proxy for bone metabolic activity, which can be used to infer locomotor activity. Long bones receive blood from three sources, …

There’S More Than One Way To Climb A Tree: Limb Length And Microhabitat Use In Lizards With Toe Pads, Travis J. Hagey, Scott Hart, Matthew Vickers, Luke J. Harmon, Lin Schwarzkopf

Biology

Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar …

Physiological Ecology Of Four Endemic Alabama Species And The Exotic Asiatic Weatherfish, Misgurnus Anguillicaudatus (Cantor, 1842), Lindsay M. White, Mark E. Meade, Benjamin A. Staton

Southeastern Fishes Council Proceedings

The occurrence of Asiatic Weatherfish, Misgurnus anguillicaudatus, in Alabama, a state known for its rich biodiversity, has generated concern among conservation managers. The current study used respirometry techniques to investigate the effects of increasing temperature on four native southeastern fishes (one cyprinid, two percids, and one elassomid) and the non-native M. anguillicaudatus. A minimum of five individuals of each species were used, and three experimental temperatures were chosen to represent spring and summer averages of northeast Alabama streams (15, 20, and 25°C). Overall, mean standard metabolic rates (SMRs) for M. anguillicaudatus were low (97.01, 127.75, and 158.50 mg …

The Interommatidial Bristle Variability Of Diptera, Kimberly Palmer

Honors College Theses

Insects of the order Diptera are a popular biological model for understanding morphological trait evolution. One area of particular interest is the development of the compound eyes. While the development of ommatidia and photoreceptors has been thoroughly studied in this case, little attention has been paid to the interommatidial bristles (IOBs) present on the eyes of some dipteran families. A preliminary survey suggested that these bristles exhibit high variability among IOB families on multiple taxonomic levels and are not uniformly present or absent in any suborder of the Diptera. To confirm this observation, I conducted a literature search to …

Tempo And Mode Of Performance Evolution Across Multiple Independent Origins Of Adhesive Toe Pads In Lizards, Travis J. Hagey, Josef C. Uyeda, Kristen E. Crandell, Jorn A. Cheney, Kellar Autumn, Luke J. Harmon

Biology

Understanding macroevolutionary dynamics of trait evolution is an important endeavor in evolutionary biology. Ecological opportunity can liberate a trait as it diversifies through trait space, while genetic and selective constraints can limit diversification. While many studies have examined the dynamics of morphological traits, diverse morphological traits may yield the same or similar performance and as performance is often more proximately the target of selection, examining only morphology may give an incomplete understanding of evolutionary dynamics. Here, we ask whether convergent evolution of pad-bearing lizards has followed similar evolutionary dynamics, or whether independent origins are accompanied by unique constraints and selective …

Costs Of Group Locomotion: How Infant-Carrying And Group Members Mediate Walking Speed Decisions In North American And East African Populations, Leah M. Bouterse

Honors Projects

A major portion of humans’ activity-based energy expenditure is taken up by locomotion, particularly walking. Humans can offset the energetic expenditure of walking in numerous ways, both evolutionary (such as changes in body shape) and culturally. Behaviorally, people can choose to walk in a variety of ways, including alone or with a group, carrying loads, and walking quickly or more slowly. All of these behaviors have energetic outcomes and as such can be important windows into how populations and groups adjust to different constraints. While sex differences in speed of paired walkers have been established by others, the dynamics of …

Characterization Of Andrenocortical Tissue Morphology, Histology, And Steroid Synthesis Among Finetooth (Carcharhinus Isodon), Blacktip (Carcharhinus Limbatus), Atlantic Sharpnose (Rhizoprionodon Terraenovae), And Bonnethead (Sphyrna Tiburo) Sharks, Danielle Elizabeth Bailey

Master's Theses

Adrenocortical (interrenal) tissue is composed of steroidogenic cells that produce corticosteroids involved in the stress response and hydromineral balance. Previous research characterizing the elasmobranch interrenal suggests that the number of interrenal bodies that produce the single primary corticosteroid, 1a-hydroxycorticosterone (1a-OHB), varies among species. However, potential species-specific differences in the amount of interrenal tissue and major steroid products produced have been understudied. To address this critical gap in our understanding of elasmobranch biology, this study examined interrenal morphology, cell structure, steroidogenic enzyme distribution (3bHSD), and steroid production in four shark species: Finetooth Carcharhinus isodon, Blacktip Carcharhinus limbatus, Atlantic Sharpnose …

Patterns Of Morphological And Molecular Evolution In The Antillean Tree Bat, Ardops Nichollsi (Chiroptera: Phyllostomidae), Roxanne J. Larsen, Peter A. Larsen, Caleb D. Phillips, Hugh H. Genoways, Gary G. Kwiecinski, Scott C. Pedersen, Carleton J. Phillips, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Species endemic to oceanic islands offer unique insights into the mechanisms underlying evolution and have served as model systems for decades. Often these species show phenotypic variation that is correlated with the ecosystems in which they occur and such correlations may be a product of genetic drift, natural selection, and/or environmental factors. We explore the morphologic and genetic variation within Ardops nichollsi, a species of phyllostomid bat endemic to the Lesser Antillean islands. Ardops nichollsi is an ideal taxon to investigate the tempo of evolution in Chiroptera, as it: is a recently derived genus in the family Phyllostomidae; contains …

Gait Changes In A Line Of Mice Artificially Selected For Longer Limbs, Leah M. Sparrow, Emily Pellattt, Sabrina S. Yu, David A. Raichlen, Herman Pontzer, Campbell Rolian

Publications and Research

In legged terrestrial locomotion, the duration of stance phase, i.e., when limbs are in contact with the substrate, is positively correlated with limb length, and negatively correlated with the metabolic cost of transport. These relationships are well documented at the interspecific level, across a broad range of body sizes and travel speeds. However, such relationships are harder to evaluate within species (i.e., where natural selection operates), largely for practical reasons, including low population variance in limb length, and the presence of confounding factors such as body mass, or training. Here, we compared spatiotemporal kinematics of gait in Longshanks, a long-legged …

Histology Of Rathke’S Glands In The Razor-Backed Musk Turtle, Sternotherus Carinatus (Chelonia: Kinosternidae), With Comments On Lamellar Bodies, S. E. Trauth

Journal of the Arkansas Academy of Science

I examined the histology and ultrastructure of Rathke’s glands in two adult male razor-backed musk turtles (Sternotherus carinatus) collected in northeastern Arkansas. This species possesses two pairs of Rathke’s glands that are embedded beneath marginal bones and are named according to their anatomical location (i.e., axillary and inguinal). These integumentary glands are similar anatomically to one another. Each gland is comprised of a single, highly vascularized secretory lobule, which is surrounded by a thin tunic of asymmetrically arranged, striated muscle. Two types of large secretory vacuoles characterize most of the holocrine cells produced by a relatively thin secretory …

Dental Biotribology: Final Thoughts And Future Directions, Zhongrong Zhou, Paul Constantino, Mark Hoffman, Mugino Kubo, Gildas Merceron, Mark Purnell, Mark F. Teaford

Faculty Publications & Research of the TUC College of Osteopathic Medicine

No abstract provided.

In Vivo Rates Of Dental Microwear Formation In Laboratory Primates Fed Different Food Items, Mark F. Teaford, Peter S. Ungar, Andrea B. Taylor, Callum F. Ross, Christopher J. Vinyard

Faculty Publications & Research of the TUC College of Osteopathic Medicine

No abstract provided.

Dental Topography And Microwear Texture In Sapajus Apella, Peter S. Ungar, Claire L. Hartgrove, Alexa N. Wimberly, Mark F. Teaford

Faculty Publications & Research of the TUC College of Osteopathic Medicine

Dental microwear texture pattern has been associated with aspects of diet for a broad range of mammalian taxa. The basic idea is that soft, tough foods are sheared with a steeper angle of approach between opposing occlusal surfaces, whereas hard, brittle items are crushed with forces perpendicular to those surfaces; and this difference is manifested in anisotropic, striated microwear textures for tough foods, and complex, pitted ones for hard objects. Other factors may, however, influence microwear texture pattern and confound diet signals. For example, if tooth surface slope influences angle of approach between opposing teeth, then perhaps wear-related changes in …

Altitude- And Sex-Specific Variation In Roosting Ecology And Thermoregulation Of Myotis Lucifugus In Yellowstone National Park, Alexandra C. Slusher

Theses and Dissertations--Forestry and Natural Resources

Fifty-nine female and six male little brown myotis (Myotis lucifugus) were radio-tagged during the summers of 2012, 2013, 2014, and 2015 in Yellowstone National Park. The grand models for daily maximum skin temperature (F_98,154 = 1.55, P = 0.007), daily minimum skin temperature (F_98,154 = 1.33, P = 0.05), and daily variation in skin temperature (F_98,154 = 1.56, P = 0.006) were significant across roost type and reproductive condition class for adult females. Roosts were classified into Types A (warmest roosts), B (roosts with largest daily temperature variance), and C (stable and cool roosts) depending …

Araucaria In The Urban Landscape: A Novel Leaning Pattern And Evidence Of Cultivated Hybridization, Jason W. Johns

Master's Theses

Our understanding of the natural world is constantly evolving and strengthening as more observations are made and experiments are performed. For example, we understand that tree stems grow toward the light (positive phototropism; Darwin 1880, Loehle 1986, Christie et al. 2013) and against gravity (negative gravitropism; Knight 1806, Hashiguchi et al. 2013). We also know that plants respond to mechanical stimulus and perturbation (thigmotropism; Braam 2005). Genes and their resulting proteins have been described to uncover some of the mechanisms for these environmental responses, but relatively speaking, we have just scratched the surface (Wyatt et al. 2013). While the discovery …

The Effect Of Cold On The Physiology Of Drosophila Larva Heart And On Synaptic Transmission At Crayfish Neuromuscular Junctions, Yuechen Zhu

Theses and Dissertations--Biology

Ectothermic animals are susceptible to temperature changes such as cold shock with seasons. To survive through a cold shock, ectotherms have developed unique strategies. My interest is focusing on the physiological function of during cold shock and prolonged cold exposure in the fruit fly (Drosophila melanogaster) and crayfish (Procambarus clarkii). I used Drosophila melanogaster as a model system to investigate cardiac function in response to modulators (serotonin, acetylcholine, octopamine, dopamine and a cocktail of modulators) in acute cold shock and chronic cold shock conditions as possible mechanism to regulate heart rate in the cold. To examine if the dampened heart …

Examining The Combined Effects Of Dissolved Oxygen, Temperature, And Body Size On The Physiological Responses Of A Model Macrobenthic Polychaete Species, Capitella Teleta, Kelsey Burns Gillam

Dissertations

While the scientific community is in consensus that coastal systems are threatened by climate change, few climate change studies test the effects of more than one variable directly related to climate change. The dissolved oxygen (DO) levels of the ocean are currently subject to both global warming and eutrophication; 94% of all hypoxia zones are expected to experience >2°C increase by 2035. This dissertation aims to examine how a model organism responds to simultaneous thermal and DO stress involving four levels of DO (100%, 70%, 50%, and 20%) saturation and three temperatures (15°C, 20°C, and 25°C).

The polychaete, Capitella teleta …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …